Apparatus for carrying out the bleaching of bast fibers



Dec. 26, 1939. P. SIEDLER ET AL 2,184,477

APPARATUS FOR CARRYING OUT THE BLEACHING OF EAST FIBERS Original FiledJan. 10, 1935 Fig.2.

ATTO Y5 Patented Dec. 26,1939

UNITED STATES APPARATUS FOR CARRYING OUT THE BLEACHING F BAS'I. FIBERSPhilipp Siedler, Erich Kayser, Helmuth Korte, and

Wilhelm Waibel, Frankfo'rt-on-the-Main, Germany, assignors to I. G.Farbenindustrie Aktiengesellschalt, Frankfort-on-the-Main, Ger- I manyoritinal application January 10, 1935, Serial- No. 1,248. Divided andthis application October 27, 1937, Serial No. 171,352.

any 20, 1934 In Germany Jan- 2 Claims. (01. 68 189)' The presentinvention relates to an apparatus for carrying out the bleaching of bastfibers, particularly on cross-wound bobbins, by chlorinating theimpurities with chlorine water. The

5 particular method of bleaching bast fibers, forwhich this apparatus issuitable, is described and claimed in the co-pending U. S. applicationSerial No. 1,248 filed January 10, 1935, in the name of Philipp Siedler,Erich Kayser, Helmuth Korte i0 and Wilhelm Waibel for A method for thebleaching of bast fibers and an apparatus therefor.

The bleaching of bast fibers with the aid of chlorine water has hithertonot been satisfac- 1 tory. The usual method was to prepare the chlorinewater separately and to pour this solution into a bleaching apparatus, aproceeding which involved loss of chlorine from the solution before thechlorine could be used, and much trouble due to the presence of chlorinein the atmosphere. Furthermore, the usual'chlorine water contains onlya. relatively low concentration of active chlorine. In bleaching bastfibers, as is known, it is primarily important to chlorinate the more orless lignified impurities which by this operation are converted into analkali-soluble condition; for this purpose the concentration of chlorinewater as previously used does not sufiice; particularly when the bastfibres to be chlorinated are placed tightly packed in any of the knownbleaching apparatus, because the chlorine water has only a lowpenetrating action.

The present invention is based upon the observation that theseinconveniences and insufficiencies of the bleaching of bast fibers withchlorine water are avoided by performing the preparation of saturated orsupersaturated chlorine water and the introduction of this chlorinewater into'the bleaching vessel in one apparatus.

40 For this purpose an apparatus for the preparation of the chlorinewater is constructed in such a manner that it may yield stronglysupersaturated chlorine water, namely so that the chlorine contained inthe apparatus is introduced into the water under a raised pressure; thisapparatus is combined with the bleaching device so as to form a closedsystem. The supersaturated chlorine water is thus caused to act directlyon the bast fibers and has no opportunity of losing chlorine in excessof saturation under atmospheric pressure.' The chlorine water may alsobe caused to act on the bast fibers under raised pressure.

It is particularly advantageous to construct the whole apparatus in sucha manner that the chlorine water circulates between the device in whichit is produced and a vessel containing the material to be bleached,streaming through the said vessel from the bottom to the top, thechlorine water thus passing all parts of the fibrous material in anequal force. The whole appara- 5 tus may be provided with means foradjusting and maintaining the concentration desired of the chlorinewater.

Within this apparatus it is possible to treat the bast fibers, be theytightly packed (hank l0 yarn) or on cross-wound bobbins, with thesupersaturated chlorine water to such an extent that the ligninsubstances are completely chlorinated. In the said apparatus such anuniform treatment of the fibers is attained that no stains are formed.15 By connecting the apparatus for the formation of supersaturatedchlorine water with the bleaching apparatus loss of chlorine is avoidedbecause the excess of chlorine is eagerly absorbed by the bodiesaccessible to the chlorination. Further- 20 more, a suflicientconcentration of the chlorine .dissolved in the water is maintained;this concntration facilitates the penetrating action of thechlorination.

In the accompanying drawing- 25 Fig. 1 is a diagrammatic view of anapparatus in accordance with the present invention, and Fig. 2 is amagnified part sectional view of one portion of Fig. 1.

The bast fibers, for instance, on cross-wound o bobbins, are containedin a suitable bleaching apparatus A through which the liquor is causedto circulate by a pump B in the direction from the bottom to the top. Inthe high-pressure piping C of the pump there may be a throttle 35 valveD. In front of this valve there is arranged a branch pipe E whichdischarges into the upper part of the apparatus F serving for thepreparation of the chlorine water. This apparatus preferably consists ofa column F charged with filling bodies. Into this column water isintroduced through the inlet pipe E while chlorine is simultaneouslyintroduced through the inlet pipe M. By filling up this column withwater and chlorine under pressure the two phases are brought into 45contact with each other in a finely divided form by the action of thefilling bodies, so that supersaturated chlorine water is formed. Fromthe lower part of the column the chlorine water is discharged throughthe pipe G into the high- 50 pressure piping C. The discharge pipe J ofthe bleaching apparatus opens into the suction pipe H of the pump. Thepipe K which may be closed by the valve L serves for drawing oil theliquor and for introducing fresh water. The apparatus 55 is operated forinstance as follows: It is filled with tap water while the valve L isopened and the valve D is closed, The valve L is then closed and thewater is caused to circulate rapidly by means of the pump B. At the sametime chlorine is introduced from a pressure bottle B through the pipe Minto the column F so that chlorine water is produced, the pressure beingadjusted according to demand. By partially opening the valve D it ispossible to regulate to a large extent the quantity of water runningthrough the column F and consequently the concentration of thechlorinewater. Through the high-pressure piping C the chlorine water leaving thecolumn F is forced into the header N whence it rises into the pipes 0having lateral openings S. On these pipes the cross-wound bobbins P areplaced. From the openings S of the pipes 0 the chlorine water isdischarged into the cross-wound bobbins through which it flows to returnby way of the pipes J and K into the pump 3. If the method of bleachinghas to be performed with application of pressure, it is necessary toprovide the lid Q of the bleaching vessel with a tightening device andto make the vessel capable of resisting pressure.

We claim:

1. An apparatus for the chlorinating and bleaching of bast fibers, forinstance linen, hemp or the like by saturated or supersaturated chlorinewater which comprises a bleaching vessel which is provided with devicestor-placing the material to be treated on cross wound bobbins, a devicefor producing said chlorine water, a system of tubes and a pump in orderto provide a continuous circulation of the chlorine water through thebleaching vessel and the device for producing the chlorine water andmeans for ad- Justlng and maintaining the concentration desired of thechlorine water.

2. An apparatus for the chlorinating and bleaching of bast fibers, forinstance linen, hemp or the like by saturated or supersaturated chlorinewater which comprises a bleaching vessel which is provided with devicesfor placing the material to be treated on cross wound bobbins, a devicefor producing said chlorine water, a system of tubes and a pump in orderto provide a continuous circulation of the chlorine water through thebleaching vessel and the device for producing the chlorine water in sucha manner that the chlorine water circulates in the bleaching vessel fromthe bottom to the top and means for adjusting and maintaining theconcentration desired of the chlorine water.

PHILIPP SIEDLER.

ERICH KAYSER. HELMUTH KORTE. WILHEIM WAIBEL.

